package com.dycong.common.leetcode.yi;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: yilin
 * Date: 2019-08-09
 * Time: 15:36
 */
public class ClimbStairs {

    public static void main(String[] args) {
        System.out.println(climbStairs(3));

    }
//    public static int climbStairs(int n) {
//        if(n==1) return 1;
//        if(n==2) return 2;
//        return climbStairs(n-1)+climbStairs(n-2);
//    }

    public static int climbStairs(int n) {
        if (n == 1) {
            return 1;
        }
        int[] dp = new int[n + 1];
        dp[1] = 1;
        dp[2] = 2;
        for (int i = 3; i <= n; i++) {
            dp[i] = dp[i - 1] + dp[i - 2];
        }
        return dp[n];
    }
}
